Lamp holder



FIG. 1 is a top, left-side front perspective view of a lamp holder embodying our new design;

FIG. 2 is a left-side elevational view thereof, the right side being mirror symmetrical thereto;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for a lamp holder, as shown and described. 